Home Drug Guide Azathioprine

Drug Guide

Generic Name

Azathioprine

Brand Names Imuran, Azasan

Classification

Therapeutic: Immunosuppressant

Pharmacological: Purine analog and immunosuppressant

FDA Approved Indications

  • Prevention of organ rejection in transplant patients
  • Treatment of rheumatoid arthritis
  • Treatment of inflammatory bowel disease (Crohn's disease and ulcerative colitis)

Mechanism of Action

Azathioprine is converted into 6-mercaptopurine in the body, which inhibits purine synthesis. This results in suppression of the immune response by decreasing lymphocyte proliferation.

Dosage and Administration

Adult: Variable based on indication; typical dose ranges from 50 to 3,000 mg/day divided doses. Dose should be individualized based on patient's clinical response and tolerability.

Pediatric: Dose varies with weight and indication; usually starting at 1-3 mg/kg/day, adjusted as needed.

Geriatric: Use with caution; start at lower doses due to increased risk of toxicity.

Renal Impairment: Adjust dosage based on renal function; consult specific guidelines.

Hepatic Impairment: Use cautiously; no specific dosing guidelines, monitor closely.

Pharmacokinetics

Absorption: Well absorbed orally.

Distribution: Widely distributed in body tissues; crosses the placenta.

Metabolism: Primarily hepatic via thiopurine methyltransferase (TPMT) and xanthine oxidase pathways.

Excretion: Renal excretion of metabolites.

Half Life: Approximately 5 hours, but active metabolites may persist longer.

Contraindications

  • Known hypersensitivity to azathioprine or 6-mercaptopurine
  • Pregnant women due to teratogenicity

Precautions

  • Monitor for myelosuppression, hepatotoxicity, and gastrointestinal toxicity; use cautiously in elderly and those with pre-existing liver disease or immune suppression.

Adverse Reactions - Common

  • Nausea (Common)
  • Leukopenia (Common)
  • Hepatotoxicity (Common)
  • Increased risk of infections (Common)

Adverse Reactions - Serious

  • Myelosuppression leading to anemia, leukopenia, thrombocytopenia (Serious)
  • Liver failure (Serious)
  • Malignancies (lymphoma, skin tumors) (Serious)

Drug-Drug Interactions

  • Allopurinol (increases azathioprine toxicity)
  • ACE inhibitors (monitor renal function)
  • Other immunosuppressants

Drug-Food Interactions

  • Alcohol (increase hepatotoxicity)

Drug-Herb Interactions

N/A

Nursing Implications

Assessment: Monitor CBC, liver function tests, renal function, and for signs of infection.

Diagnoses:

  • Risk for infection
  • Impaired liver function
  • Risk for bleeding

Implementation: Administer with food to reduce gastrointestinal upset; monitor blood counts regularly; avoid live vaccines.

Evaluation: Assess for signs of therapeutic efficacy and toxicity, adjust dose accordingly.

Patient/Family Teaching

  • Report signs of infection or unusual bleeding immediately
  • Avoid live vaccines and to practice good hygiene
  • Inform about potential side effects and the importance of regular blood tests

Special Considerations

Black Box Warnings:

  • Increased risk of malignancy, especially lymphoma and skin tumors

Genetic Factors: TPMT enzyme activity influences drug toxicity; testing recommended before initiation.

Lab Test Interference: May cause false-positive tests for urinary catecholamines.

Overdose Management

Signs/Symptoms: Severe myelosuppression, hepatotoxicity, bone marrow suppression, infections.

Treatment: Supportive care, stop medication, administer leucovorin as an antidote if appropriate, monitor blood counts and organ function.

Storage and Handling

Storage: Store at room temperature, away from moisture and light.

Stability: Stable until expiration date on container.

🛡️ 5 Critical Medication Safety Tips for Nurses

1

Triple-Check High-Risk Medications

Always have another nurse verify insulin, heparin, warfarin, and chemotherapy drugs. These "high-alert" medications cause the most serious errors. Check concentration, dose calculation, and pump settings twice.

2

Know Look-Alike, Sound-Alike Drugs

Common mix-ups: hydromorphone/morphine, Celebrex/Celexa, Zyprexa/Zyrtec. Always use BOTH generic and brand names, read labels twice, and use barcode scanning when available. One wrong letter can be fatal.

3

Assess Before AND After Giving Meds

Check vitals before cardiac meds, pain levels before analgesics, and blood glucose before insulin. Always reassess within 30 minutes to evaluate effectiveness and watch for adverse reactions.

4

Watch for Drug Interactions

Common dangerous combinations: warfarin + aspirin (bleeding), ACE inhibitors + potassium (hyperkalemia), digoxin + diuretics (toxicity). Always check drug interactions before administering new medications.

5

Educate Your Patients

Teach patients medication names, purposes, major side effects, and what to report. Informed patients catch errors and improve compliance. Always encourage questions - an educated patient is a safer patient.

⚡ Remember: When in doubt, don't give it out! It's always safer to double-check than regret later.

⚠️ Medical Disclaimer

This drug guide is for educational purposes only and is NOT intended for clinical use. Always consult current prescribing information, healthcare providers, and institutional protocols before administering any medication. Do not use this information for patient care decisions.